1. Field of the Invention
The present invention relates to a method of casting and rolling and a roll stand arrangement for rolling finished sections (sheet piling sections) from a preliminary section which arrives from a continuous casting machine and has the approximate final dimensions. The method utilizes roll stand arrangements which operate in a rolling line in a reversing operation. The roll stand arrangements include a compact rolling group composed of a first universal stand at an entry side and a second universal stand at an exit side and an intermediate edging stand arranged between the universal stands, wherein a roughing rolling group composed of vertical roll stands and horizontal roll stands is arranged in front of the compact rolling group. For rolling the sheet piling sections, with one of the roll stands of the roughing rolling group and one of the roll stands of the compact rolling group being equipped with selectable grooves which can be optionally moved into and out of the rolling line, shaping of the preliminary section in the roll stands of the roughing group is carried in a number of shape changing passes and shape reduction passes, and subsequently further shaping of the section is carried in the compact rolling group in several shape changing passes or shape reduction passes and reversing passes in the universal stand on the entry side and in the intermediate edging stand with or without the use of the selectable grooves, wherein the compact rolling group operates as a tandem stand group.
2. Description of the Related Art
The rolling of sheet piling sections has in the past always been carried out with reversing operations in rolling trains with individual stands and free runout of the roll stand because the large number of shaping grooves necessary for the roughing rolling of such sections required large reversing roll stands with great lengths of the bodies of the rolls for accommodating the number of shaping grooves. These large stands and the rolls themselves, as well as the necessary manipulating devices for introducing the rolling stock into the various grooves are very complicated, require a large amount of space and have relatively low throughput capacities. The large quantities of rolling stock themselves lead to relatively long rolling times during reversing rolling and they practically do not make it possible to operate such plants in a timed sequence with a continuous casting machine. For this reason, relatively large intermediate storage facilities are required when continuous casting plant and rolling mill are used together.
Therefore, for rolling of sheet piling sections, it has already been proposed in a not prepublished older patent application to use a compact rolling group composed of a tandem stand each on the entry side and the exit side each having two-high roll pairs with two or more grooves and corresponding transverse shifting devices for the rolling stock and an intermediate edging stand with or without selectable grooves arranged between the two tandem stands, wherein the preshaped preliminary section is shaped in a section-changing manner in the universal stand possibly equipped with profiled horizontal rolls and in the horizontal two-high stand of the roughing rolling group also possibly equipped with profiled horizontal rolls in several reversing passes between the two roll stands,a nd the section is subsequently finish-shaped in a reversing operation in the grooves of the two tandem stands with or without the inclusion of a pass in the intermediate edging stand having profiled rolls.
However, these and similar methods and roll stand arrangements make it only possible to achieve relatively small productions and the guidance of the section already shaped by rolling in the tandem stands posed technical difficulties. It is essentially only possible to produce sheet piling sections having U-shaped cross-sections, but not those with Z-shaped cross-sections for which there is a great demand today in various markets.